/***
 *  不常用组件生命周期之 etDerigviedStateFromProps
 *  将props和state进行关联 映射
 *
 */
import React, { Component } from 'react'

export default class App extends Component {
    render() {
        return (
            <div>
                父组件
                <Child msg="父组件传递的参数"></Child>
            </div>
        )
    }
}

class Child extends Component {
    // state = this.props
    // 将props映射到state中 产生关联
    static getDerivedStateFromProps(props, state) {
        console.log(props)
        console.log(state)
        //   // 返回值 将赋值给state
        return { msg: props.msg }
    }
    render() {
        // console.log(this.props)
        return <div>子组件-{this.state.msg}</div>
    }
}
